Microgram Journal, Volume 8, Number 1 29 In most forensic laboratories, the solvents used to extract drugs are chosen based upon their solubility properties and their ability to not interact with the drug. In fact, there are very few publications where a solvent used to extract a drug reacts with the drug and forms by-products [1-3]. This laboratory recently discovered that an additional component was formed when acetone was used to extract a sample containing a known tryptamine. Analysis by gas chromatography/mass spectroscopy (GC/MS) of the acetone extract yielded an extra peak in the total ion chromatogram that was approximately half the abundance of the known tryptamine peak. The known tryptamine peak was identified from the fragmentation pattern and retention time. The unknown peak’s fragmentation pattern exhibited a molecular ion that was 40 mass units higher than that of the known tryptamine molecular ion and was subsequently identified as the imine formed from the reaction with acetone. Primary aliphatic amines are known to react with aldehydes and ketones, typically in the presence of an acid catalyst, to produce an imine, or a carbon-nitrogen double bond, Figure 1 [4, 5]. This study reports that the following phenethylamines, amphetamines, and tryptamines form imines with acetone under mild conditions: phenethylamine; 2,5-dimethoxy-4-iodo- phenethylamine (2C-I); 2,5-dimethoxy-4-ethylthio- phenethylamine (2C-T-2); 2,5-dimethoxy-4-ethyl- phenethylamine (2C-E); 2,5-dimethoxy-4-n-propylthio- - phenethylamine (2C-T-7); 2,5-dimethoxy-4-chloro- phenethylamine (2C-C); 2,5-dimethoxy-4-bromo- phenethylamine (2C-B); 2,5-dimethoxyamphetamine; 4-methoxyamphetamine, 3,4-methylenedioxyamphetamine (MDA); amphetamine; tryptamine; α-methyl-tryptamine; and 5-methoxy-α-ethyl-tryptamine. This study also reports that the GC/MSD of all imine compounds showed preferential cleavage at the α-carbon on the alkyl chain. In addition to GC/MS, the imines formed from phenethylamine base and tryptamine base were characterized by Fourier transform-infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Experimental Solvents, Chemicals, and Materials Acetone was ACS/HPLC grade from Burdick and Jackson Laboratories (Muskegon, MI). Phenethylamine base and tryptamine base were obtained from Sigma-Aldrich Chemicals (Milwaukee, WI). All other compounds were obtained from the authentic reference collection of the DEA Special Testing and Research Laboratory. Gas Chromatography/Mass Spectrometry (GC/MS) GC/MS analyses were performed using an Agilent Model 5975C inert XL mass-selective detector (MSD) interfaced with an Agilent Model 7890A gas chromatograph. The GC system was fitted with a 30 m x 0.250 mm ID fused-silica capillary column coated with HP-5 (0.25 μm) supplied by J & W Scientific. The injection port temperature was maintained at 280ºC and was operated in the split mode (25:1). The oven temperature was programmed as follows: initial temperature, 90ºC; initial hold, 2 minutes; program rate 14ºC/minute; final temperature, 300ºC; final hold, 10 minutes. The MSD was operated in the electron ionization (EI) mode with an ionization potential of 70 eV, a scan range of 34-550 mass units, and at 2.83 scans/second. The MS source and MSD were maintained at 230ºC and 150ºC, respectively. Fourier Transform-Infrared Spectroscopy (FTIR) FTIR analyses were performed using a Thermo Scientific Model Smart Golden Gate attenuated total reflectance (ATR) Detection of Phenethylamine, Amphetamine, and Tryptamine Imine By-Products from an Acetone Extraction Mary A. Yohannan* and Arthur Berrier U.S. Department of Justice Drug Enforcement Administration Special Testing and Research Laboratory 22624 Dulles Summit Court Dulles, VA 20166 [email: mary.a.yohannan -at- usdoj.gov] ABSTRACT: The formation of imine by-products from phenethylamines, amphetamines, and tryptamines upon an acetone extraction is presented. These imine by-products were characterized using GC/MSD and exhibited preferential cleavage at the α-carbon of the alkyl chain. Further characterization of the imine by-products of phenethylamine and tryptamine was done using IR and NMR. KEYWORDS: phenethylamine, tryptamine, imine, acetone, schiff base, drug chemistry, forensic chemistry Figure 1 - Simple reaction of a primary amine with acetone to produce an imine.
7
Embed
Detection of Phenethylamine, Amphetamine, and Tryptamine … · 2018. 5. 20. · products of phenethylamine and tryptamine were formed. Also, there was no indication that any acetone
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Microgram Journal, Volume 8, Number 1 29
In most forensic laboratories, the solvents used to extract
drugs are chosen based upon their solubility properties and their
ability to not interact with the drug. In fact, there are very few
publications where a solvent used to extract a drug reacts with
the drug and forms by-products [1-3].
This laboratory recently discovered that an additional
component was formed when acetone was used to extract a
sample containing a known tryptamine. Analysis by gas
chromatography/mass spectroscopy (GC/MS) of the acetone
extract yielded an extra peak in the total ion chromatogram that
was approximately half the abundance of the known tryptamine
peak. The known tryptamine peak was identified from the
fragmentation pattern and retention time. The unknown peak’s
fragmentation pattern exhibited a molecular ion that was 40
mass units higher than that of the known tryptamine molecular
ion and was subsequently identified as the imine formed from
the reaction with acetone. Primary aliphatic amines are known
to react with aldehydes and ketones, typically in the presence of
an acid catalyst, to produce an imine, or a carbon-nitrogen
double bond, Figure 1 [4, 5].
This study reports that the following phenethylamines,
amphetamines, and tryptamines form imines with acetone under